The body of a Chaldean Catholic archbishop who was abducted by gunmen last month was discovered Thursday in the northern Iraqi city of Mosul, and a car bomb killed 18 people in Baghdad.

Mosul Archbishop Paulos Faraj Rahho's body was found by police in the city's Intisar neighborhood. Gunmen grabbed him Feb. 29 after he had finished celebrating the Stations of the Cross, killing three of his bodyguards.

There were conflicting accounts Thursday night of the cause of his death, whether from ill health or injuries suffered when he was seized.

Church sources told AsiaNews, a Catholic news service, that the death of the 67-year-old Rahho, who had suffered a heart attack a couple of years ago and was in poor health, probably was caused by the lack of his medication. They told the agency, which specializes in the Middle East, that his body showed no signs of violence and that an autopsy revealed he had been dead for at least five days.

However, Nineveh's provincial police chief, Gen. Wathiq Hamdani, said that police found Rahho's body in the street and that he had been shot.

"He was wounded when they killed his security and as a result he died," Hamdani said.

Nineveh Deputy Gov. Khasro Goran said Rahho's killers probably had pretended for days that he was alive in hope of getting a ransom.

"It's not the first time Christian bishops have been targeted by these organizations," he said.

Both Hamdani and Goran blamed the militant group Al Qaeda in Iraq for the archbishop's death.

The kidnappers had demanded millions of dollars, weapons and the release of Arab inmates in Kurdish prisons, the news service reported.

Rahho, in a fall interview with the news agency, said he thought Christians in Mosul encountered great risks because of their faith, which groups such as Al Qaeda in Iraq consider inferior to Islam.

"Everyone is suffering from this war irrespective of religious affiliation, but in Mosul Christians face starker choices," Rahho said.

In June, a priest and three deacons were fatally shot outside their church in Mosul. Two priests were kidnapped and released in October in the northern city. Several of the city's churches and affiliated buildings were targeted in January bombings.

Before the U.S.-led invasion in 2003, Iraqi Christians were estimated to number about 800,000, but many have fled the country. Their churches have been attacked and members assassinated or expelled from their homes by Islamic extremists.

The Chaldean church pledges fealty to the Vatican.

Pope Benedict XVI condemned the archbishop's death, calling it "an act of inhuman violence that offends the dignity of mankind and does grave harm to the cause of brotherly coexistence among the beloved Iraqi people."

Assyrian Christian politician Romeo Hakkari, a member of the Kurdistan regional parliament, warned that Iraq's Christians were under siege.

"There is a great threat to Christians as a religion and ethnicity. I don't recall a day in Iraq's history where Christians were being killed like today," Hakkari said. "This is conspiracy by the Islamic radical group of Al Qaeda to annihilate Christians."

Iraqi Prime Minister Nouri Maliki and President Jalal Talabani also offered their condolences.

In Baghdad, the bombing Thursday near the popular Tahrir Square followed a double suicide bombing last week in the Karada district, which killed 68 people. A blast Monday claimed the lives of five U.S. soldiers in west Baghdad.

Witnesses to Thursday's attack said the car that exploded was parked and the blast did not appear to be the work of a suicide bomber. It wreaked havoc in the commercial area near Baghdad's high-security Green Zone.

Raheem Kareem, 36, who sells cellphones, said the explosion sent glass flying into his shop.

"It was a huge explosion. I had injuries all over my body," said Kareem, who was hospitalized.

U.S. military commanders have said the recent escalation in violence in Iraq does not signal an end to the period of decline seen since September.

Gen. David H. Petraeus, the senior U.S. commander in Iraq, said Wednesday that he suspected Sunni extremists were launching attacks in Baghdad to distract the American and Iraqi forces from Nineveh province, where many militants had fled.

"This is a very astute enemy and they know that the trends have been almost uniformly positive now for about six or seven or so months, so it may be that they are trying to put a dent into that. They also learn and adapt," Petraeus said. "I mean they are resilient, very, very resilient enemies. And we should expect more of that. There's no silver bullet that we can shoot at organizations like Al Qaeda and some of their Sunni insurgent confederates."

Also Thursday, an Iraqi journalist working for a local newspaper was fatally shot as he drove through Baghdad's Karada district, considered one of the capital's safer neighborhoods, Iraq's journalism union said.

A suicide bomber tried to attack a meeting of Sunni fighters aligned with the Americans in Zab Nahia, a community 28 miles southwest of Kirkuk, but was blocked from entering the house. The attacker, identified as a woman by the U.S. military, killed two civilians and wounded seven guards outside the gathering of Sunni tribal leaders and former insurgents who have teamed up with the U.S. military to police their areas and fight Al Qaeda in Iraq.

The U.S. military also said it had accidentally killed an Iraqi girl Wednesday in Diyala province when soldiers fired a warning shot at a woman they thought was signaling suspiciously to someone. Military officials said the incident was under investigation.

Parker reported from Baghdad and Wilkinson from Rome. Times staff writers Alexandra Zavis and Saif Hameed, special correspondent Asso Ahmed in Sulaymaniya and a special correspondent in Mosul contributed to this report.

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